scholarly journals Role of Src homology 2 domain-mediated PTK signaling in mouse zygotic development

Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 413-421 ◽  
Author(s):  
Li Meng ◽  
JinPing Luo ◽  
Chunhua Li ◽  
William H Kinsey
Keyword(s):  
Marine Invertebrates ◽  
Sh2 Domain ◽  
Calcium Oscillations ◽  
Src Family Kinases ◽  
Developmental Potential ◽  
Fyn Kinase ◽  
Src Homology 2 ◽  
Src Homology ◽  
Src Homology 2 Domain

Fyn and other Src-family kinases play an essential role at several steps during egg activation following fertilization of externally fertilizing species, such as marine invertebrates, fish, and frogs. Recent studies demonstrate that the requirement for Src-family kinases in activation of the mammalian egg is different from lower species, and the objective of this study was to test the role of the Fyn kinase in the mouse egg activated by intracytoplasmic sperm injection (ICSI). An Src homology 2 (SH2) domain containing fusion protein was used to suppress Fyn function in the mouse zygote following ICSI. Eggs injected with the Fyn SH2 domain at an intracellular concentration of 4–8 μM exhibited reduced developmental potential with 100% of the zygotes being arrested following the first or the second cleavage. At higher concentrations, the protein blocked pronuclear congression and the zygotes remained at the pronuclear stage. The SH2 domain had no effect on sperm-induced calcium oscillations in distinct contrast to its effect on the eggs of lower species. The results indicate that the SH2 domain of Fyn kinase plays an important role in pronuclear congression as well as early cleavage events and that this effect appears not to involve disruption of calcium oscillations.

Src Homology 2 Domain Binding as a Phosphoproteomic Approach to Signaling in Acute Lymphoblastic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4442-4442
Author(s):  
Martin A. Horstmann ◽  
Peter Nollau
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Adaptor Proteins ◽  
Sh2 Domain ◽  
Effector Proteins ◽  
Sh2 Domains ◽  
Binding Domains ◽  
Src Homology 2 ◽  
Src Homology ◽  
Src Homology 2 Domain

Abstract A general theme of orchestrated signal transduction is played by activated receptor phosphotyrosine kinases (PTK) and receptor PTK targets which propagate signals via recognition of sequence-specific phoshorylated tyrosines by so-called Src homology 2 (SH2) domains. SH2 domain interactions are used as a means of recruiting target proteins to activated PTKs and to translocate them to the plasma membrane where many effector proteins activated by receptor PTKs such as phospholipase C-γ or PI-3 kinase have their substrates. SH2 domains make up the most prevalent type of phosphotyrosine binding domains involved in signaling downstream of activated PTKs. SH2 domains are not only present in proteins with intrinsic enzymatic activity but also in adaptor proteins which shuttle effector enzymes to target signaling complexes. Increasing numbers of diseases are known to involve phosphotyrosine specific kinases and/or phosphatases going awry exemplified by the notorious ErbB2 receptor PTK in breast cancer or the Bcr-Abl PTK in CML. Currently, the tyrosine phosphorylation state in most acute lymphoblastic leukemias is undefined which is predicted to differ among the various subgroups and to be distinct from the signaling state of normal hematopoietic cells. To identify aberrant tyrosine kinase or phosphatase activity in the various types of acute lymphoblastic leukemia is of great interest since enzymes in general make good targets for drugs. A novel SH2 domain binding approach is presented which can detect distinctive profiles of tyrosine-phosphorylated proteins in complex mixtures of cellular proteins. A battery of SH2 domains is employed as probes in a competitive far-Western blot based assay to identify specific tyrosine-phosphorylated sites which reflect active signaling pathways in a cell. A further refinement of this technology is under way with DNA-tagged probes being developed which allow for multiplexing and high throughput quantitative assessment of SH2-domain binding by quantitative PCR or microarray technologies.

scholarly journals Multiple stimuli induce tyrosine phosphorylation of the Crk-binding sites of paxillin

2001 ◽  
Vol 360 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Michael D. SCHALLER ◽  
Erik M. SCHAEFER
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Phosphorylation ◽  
Binding Sites ◽  
Signalling Molecules ◽  
Src Homology 2 ◽  
Dependent Cell ◽  
Src Homology ◽  
Tyrosine Phosphorylated Protein ◽  
Src Homology 2 Domain

Paxillin is a focal-adhesion-associated, tyrosine-phosphorylated protein. In cells transformed by the src, crk or BCR-Abl oncogenes, the phosphotyrosine content of paxillin is elevated. In normal cells paxillin functions in signalling following integrin-dependent cell adhesion or exposure to a number of stimuli, including growth factors and neuropeptides. These stimuli induce tyrosine phosphorylation of paxillin, regulating the association of Src homology 2 domain-containing signalling molecules with paxillin. There are multiple sites of tyrosine phosphorylation on paxillin. To elucidate the role of paxillin in transducing signals in response to various stimuli, it is essential to identify all of the sites of phosphorylation on paxillin and to define which residues are phosphorylated in response to distinct stimuli. We describe two new sites of tyrosine phosphorylation on paxillin, residues at positions 40 and 88. Using paxillin variants with phenylalanine substitutions at phosphorylation sites and phospho-specific paxillin antibodies, tyrosine phosphorylation of paxillin in response to distinct stimuli was examined. The results demonstrate that Tyr31 and Tyr118, which are binding sites for Crk, are major sites of tyrosine phosphorylation following cell adhesion or stimulation with platelet-derived growth factor or angiotensin II. Thus multiple stimuli may elicit similar signalling events downstream of paxillin.

scholarly journals B Cell Adaptor Containing Src Homology 2 Domain (Bash) Links B Cell Receptor Signaling to the Activation of Hematopoietic Progenitor Kinase 1

2001 ◽  
Vol 194 (4) ◽  
pp. 529-540 ◽  
Author(s):  
Sachiyo Tsuji ◽  
Mariko Okamoto ◽  
Koichi Yamada ◽  
Noriaki Okamoto ◽  
Ryo Goitsuka ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Tyrosine Phosphorylation ◽  
Phosphorylation Site ◽  
Sh2 Domain ◽  
Hematopoietic Progenitor ◽  
Src Homology 2 ◽  
Bcr Signaling ◽  
Src Homology ◽  
Src Homology 2 Domain

The B cell adaptor containing src homology 2 domain (BASH; also termed BLNK or SLP-65), is crucial for B cell antigen receptor (BCR)-mediated activation, proliferation, and differentiation of B cells. BCR-mediated tyrosine-phosphorylation of BASH creates binding sites for signaling effectors such as phospholipase Cγ (PLCγ)2 and Vav, while the function of its COOH-terminal src homology 2 domain is unknown. We have now identified hematopoietic progenitor kinase (HPK)1, a STE20-related serine/threonine kinase, as a protein that inducibly interacts with the BASH SH2 domain. BCR ligation induced rapid tyrosine-phosphorylation of HPK1 mainly by Syk and Lyn, resulting in its association with BASH and catalytic activation. BCR-mediated activation of HPK1 was impaired in Syk- or BASH-deficient B cells. The functional SH2 domain of BASH and Tyr-379 within HPK1 which we identified as a Syk-phosphorylation site were both necessary for interaction of both proteins and efficient HPK1 activation after BCR stimulation. Furthermore, HPK1 augmented, whereas its kinase-dead mutant inhibited IκB kinase β (IKKβ) activation by BCR engagement. These results reveal a novel BCR signaling pathway leading to the activation of HPK1 and subsequently IKKβ, in which BASH recruits tyrosine-phosphorylated HPK1 into the BCR signaling complex.

scholarly journals A Regulatory Role for Src Homology 2 Domain–Containing Inositol 5′-Phosphatase (Ship) in Phagocytosis Mediated by Fcγ Receptors and Complement Receptor 3 (αMβ2; Cd11b/Cd18)

2000 ◽  
Vol 193 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Dianne Cox ◽  
Benjamin M. Dale ◽  
Masaki Kashiwada ◽  
Cheryl D. Helgason ◽  
Steven Greenberg
Keyword(s):  
Cell Model ◽  
Complement Receptor ◽  
Phosphatidylinositol 3 Kinase ◽  
Src Homology 2 ◽  
Catalytically Active ◽  
Src Homology ◽  
Complement Receptor 3 ◽  
Phagocytic Cups ◽  
Src Homology 2 Domain

The Src homology 2 domain–containing inositol 5′-phosphatase (SHIP) is recruited to immunoreceptor tyrosine-based inhibition motif (ITIM)–containing proteins, thereby suppressing phosphatidylinositol 3-kinase (PI 3-kinase)–dependent pathways. The role of SHIP in phagocytosis, a PI 3-kinase–dependent pathway, is unknown. Overexpression of SHIP in macrophages led to an inhibition of phagocytosis mediated by receptors for the Fc portion of IgG (FcγRs). In contrast, macrophages expressing catalytically inactive SHIP or lacking SHIP expression demonstrated enhanced phagocytosis. To determine whether SHIP regulates phagocytosis mediated by receptors that are not known to recruit ITIMs, we determined the effect of SHIP expression on complement receptor 3 (CR3; CD11b/CD18; αMβ2)–dependent phagocytosis. Macrophages overexpressing SHIP demonstrated impaired CR3-mediated phagocytosis, whereas macrophages expressing catalytically inactive SHIP demonstrated enhanced phagocytosis. CR3-mediated phagocytosis in macrophages derived from SHIP−/− mice was up to 2.5 times as efficient as that observed in macrophages derived from littermate controls. SHIP was localized to FcγR- and CR3-containing phagocytic cups and was recruited to the cytoskeleton upon clustering of CR3. In a transfected COS cell model of activation-independent CR3-mediated phagocytosis, catalytically active but not inactive SHIP also inhibited phagocytosis. We conclude that PI 3-kinase(s) and SHIP regulate multiple forms of phagocytosis and that endogenous SHIP plays a role in modulating β2 integrin outside-in signaling.

scholarly journals The role of the Src Homology-2 domain containing protein B (SHB) in β cells

2015 ◽  
Vol 56 (1) ◽  
pp. R21-R31 ◽  
Author(s):  
Michael Welsh ◽  
Maria Jamalpour ◽  
Guangxiang Zang ◽  
Björn Åkerblom
Keyword(s):  
Cell Function ◽  
Cell Types ◽  
Receptor Activation ◽  
Sh2 Domain ◽  
Adaptive Responses ◽  
Src Homology 2 ◽  
Β Cell Function ◽  
Src Homology ◽  
Src Homology 2 Domain ◽  
Protein B

This review will describe the SH2-domain signaling protein Src Homology-2 domain containing protein B (SHB) and its role in various physiological processes relating in particular to glucose homeostasis and β cell function. SHB operates downstream of several tyrosine kinase receptors and assembles signaling complexes in response to receptor activation by interacting with other signaling proteins via its other domains (proline-rich, phosphotyrosine-binding and tyrosine-phosphorylation sites). The subsequent responses are context-dependent. Absence ofShbin mice has been found to exert effects on hematopoiesis, angiogenesis and glucose metabolism. Specifically, first-phase insulin secretion in response to glucose was impaired and this effect was related to altered characteristics of focal adhesion kinase activation modulating signaling through Akt, ERK, β catenin and cAMP. It is believed that SHB plays a role in integrating adaptive responses to various stimuli by simultaneously modulating cellular responses in different cell-types, thus playing a role in maintaining physiological homeostasis.

scholarly journals Crystal structure of an SH2–kinase construct of c-Abl and effect of the SH2 domain on kinase activity

2015 ◽  
Vol 468 (2) ◽  
pp. 283-291 ◽  
Author(s):  
Sonja Lorenz ◽  
Patricia Deng ◽  
Oliver Hantschel ◽  
Giulio Superti-Furga ◽  
John Kuriyan
Keyword(s):  
Crystal Structure ◽  
Functional Role ◽  
Kinase Activity ◽  
Sh2 Domain ◽  
Constitutive Activation ◽  
Src Homology 2 ◽  
Kinase C ◽  
Src Homology

Constitutive activation of the tyrosine kinase c-Abl in the cell involves interactions between the SH2 (Src-homology 2) and kinase domains (KDs). We present a crystal structure of a c-Abl construct comprising these domains and analyse the functional role of their interface in vitro.

scholarly journals Role of SHPS-1 in the Regulation of Insulin-like Growth Factor I–stimulated Shc and Mitogen-activated Protein Kinase Activation in Vascular Smooth Muscle Cells

2005 ◽  
Vol 16 (7) ◽  
pp. 3353-3364 ◽  
Author(s):  
Yan Ling ◽  
Laura A. Maile ◽  
Jaroslava Lieskovska ◽  
Jane Badley-Clarke ◽  
David R. Clemmons
Keyword(s):  
Tyrosine Phosphatase ◽  
Mitogen Activated Protein Kinase ◽  
Mutant Form ◽  
Mapk Phosphorylation ◽  
Src Homology 2 ◽  
Igf I ◽  
Mitogen Activated Protein ◽  
Src Homology ◽  
Src Homology 2 Domain

Insulin-like growth factor I (IGF-I) stimulates smooth muscle cell (SMC) proliferation, and the mitogen-activated protein kinase (MAPK) pathway plays an important role in mediating IGF-I–induced mitogenic signaling. Our prior studies have shown that recruitment of Src homology 2 domain tyrosine phosphatase (SHP-2) to the membrane scaffolding protein Src homology 2 domain–containing protein tyrosine phosphatase substrate-1 (SHPS-1) is required for IGF-I–dependent MAPK activation. The current studies were undertaken to define the upstream signaling components that are required for IGF-I–stimulated MAPK activation and the role of SHPS-1 in regulating this process. The results show that IGF-I–induced Shc phosphorylation and its subsequent binding to Grb2 is required for sustained phosphorylation of MAPK and increased cell proliferation in SMCs. Furthermore, for Shc to be phosphorylated in response to IGF-I requires that Shc must associate with SHPS-1 and this association is mediated in part by SHP-2. Preincubation of cells with a peptide that contains a phospho-tyrosine binding motif sequence derived from SHPS-1 inhibited IGF-I–stimulated SHP-2 transfer to SHPS-1, the association of Shc with SHPS-1, and IGF-I–dependent Shc phosphorylation. Expression of an SHPS-1 mutant that did not bind to Shc or SHP-2 resulted in decreased Shc and MAPK phosphorylation in response to IGF-I. In addition, SMCs expressing a mutant form of the β3 subunit of the αVβ3, which results in impairment of SHP-2 transfer to SHPS-1, also showed attenuated IGF-I–dependent Shc and MAPK phosphorylation. Further analysis showed that Shc and SHP-2 can be coimmunoprecipitated after IGF-I stimulation. A cell-permeable peptide that contained a polyproline sequence from Shc selectively inhibited Shc/SHP-2 association and impaired Shc but not SHP-2 binding to SHPS-1. Exposure to this peptide also inhibited IGF-I–stimulated Shc and MAPK phosphorylation. Cells expressing a mutant form of Shc with the four prolines substituted with alanines showed no Shc/SHPS-1 association in response to IGF-I. We conclude that SHPS-1 functions as an anchor protein that recruits both Shc and SHP-2 and that their recruitment is necessary for IGF-I–dependent Shc phosphorylation, which is required for an optimal mitogenic response in SMCs.

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